Why do I have to set prerender = true with adapter-static ?

[guillaume-mueller]

It seems to me redundant. When prerender is not set, the run build complains "all routes must be fully prerenderable", so why do I have to set a parameter I have no choice on the value ?

Creating a project via npx sv create in choosing adapter-static then without having touched anything launching run build fails because prerender is not set.

Isn't it a design flaw and a source of confusion ?

EDIT: I understand here that there is something about that it could fallback to SPA, but I don't understand in what SPA wouldn't be compatible with prerendering.